2.0

Table Of Contents
Outputting Data in the HEC-2 Format
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To plot single sections
1 From the Hydrology menu, choose HEC2 Output ä Plot Single Section.
NOTE
If no current surface is in use, then the Select Surface dialog box is
displayed. Select the surface on which to base the cross sections in the
Select Surface box, and then click OK to continue.
The following prompt is displayed:
First point (or Entity):
2 Do one of the following to select the cross section line:
n
Type Entity and press ENTER, and then select the cross section line.
n
Select the points to define the cross section line.
The Plot X-Section dialog box is displayed.
3 Establish the settings for plotting the cross section data in a graph. For more
information about the settings in this dialog box, see Changing the Hydrology
Plotting Settings in this chapter.
If you saved settings from a previous session and you want to use them for this
graph, click Load and choose the file that contains the settings.
4 After you establish the settings, click Plot to plot the cross section in the
drawing.
TIP
You can also click Preview to see what the graph looks like before actually
plotting it.
5 Select an insertion point for the graph in the drawing.
The graph is inserted in the drawing at the point you selected and the Plot X-
Section dialog box displays. At this point, you can change the plotting
parameters, if necessary, and plot the section again.
6 To plot another section, click Next Section or Close, and then select another
section line, or press ENTER to end the command.
Outputting Data in the HEC-2 Format
The HEC-2 analysis program was designed to calculate water surface profiles for
steady, gradually varying flow, in natural or man-made channels. Developed by
the Hydrologic Engineering Center (HEC), HEC-2 analysis lets you include
calculations to account for various obstructions such as bridges, culvert work,
and other structures in the flood plain.
Using HEC-2 Output commands you can sample sections from an AutoCAD
Land Development Desktop surface and output the data into a HEC-2 input file.
You can then use these files in the HEC-2 program for analysis.
The data records (GR records) specify the elevation and station of each point in
a cross section used to describe the ground profile, and are required for each X1
record unless NUMST(X1.2) is zero. The points outside the channel (referred to
as the overbank) determine the subdivision of the cross section, which
influences calculation of a discharge-weighted velocity head for the cross